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Home Topics Infectious Diseases Infections A-Z Botulism General Information ›  Wound botulism cases associated with injecting drug use

Wound botulism cases associated with injecting drug use


In 2012 there were two reports of probable or confirmed cases of wound botulism among people who inject drugs in the United Kingdom. Up to the end of 2011 a total of 163 cases had been reported since the first case of wound botulism associated with injecting drug use was reported in March 2000 (data is published in the Shooting Up report).

Causative Organism

The symptoms of botulism are caused by a toxin produced by the anaerobic spore forming bacterium Clostridium botulinum. The toxin blocks the release of acetycholine at the neuromuscular junction resulting in a descending flaccid paralysis. Botulism is not spread from one person to another.
There are three main forms of botulism:

  • Food-borne botulism, caused by ingestion of pre-formed toxin.
  • Wound botulism, which occurs when C. botulinum spores contaminate a wound, germinate and produce toxin in vivo.
  • Intestinal colonisation botulism, usually seen in infants, caused by growth of C. botulinum and production of toxin in vivo.

Clinical Features

The key clinical syndrome produced by botulinum toxin is an afebrile, descending, flaccid paralysis. Patients with botulism typically present with difficulty speaking, seeing and/or swallowing. They may have double vision, blurred vision, drooping eyelids, slurred speech, difficulty swallowing, and muscle weakness. If untreated, paralysis may progress to the arms, legs, trunk and respiratory muscles. There is usually no fever, no loss of sensation and no loss of awareness. There may also be autonomic signs with dry mouth, fixed or dilated pupils, and cardiovascular, gastrointestinal and urinary autonomic dysfunction. If onset is very rapid, there may be no symptoms before sudden respiratory paralysis occurs, which may be fatal. Recovery can take months. Clinicians should suspect botulism in any patient with an afebrile, descending, flaccid paralysis.

Laboratory Diagnosis

Confirmation of the clinical diagnosis is by the demonstration of botulinum toxin in blood samples or, in the case of wound botulism, by the identification of C. botulinum in wound specimens. Routine laboratory tests are not helpful and specimens should therefore be sent immediately to the reference laboratory.

Samples to be taken from acutely ill patients include:

  • Serum. At least 10ml. Serum samples must be collected before antitoxin is administered.
  • Wound. Pus. As much as possible in a sterile container. If pus is not available, a swab of the lesion should be taken and put immediately into a transport medium for anaerobic culture.
  • Biopsy tissues. If surgical debridement is performed, biopsy tissues should be placed immediately into a sterile container.
  • Post mortem specimens. Heart blood (10ml), if not haemolysed, should be sent for serum for serum collection. Specimens from infected wounds may also be useful.

All samples must be kept refrigerated after collection.

All specimens should be sent directly to the reference laboratory with the sender's name and address clearly marked. The reference laboratory should be telephoned prior to sending the sample.

Gastrointestinal Bacteria Reference Unit
Foodborne Pathogens Reference Section (FPRS)
Public Health England
61 Colindale Avenue
Tel: (44) 020 8327 6505

Out of office hours, laboratory personnel can be contacted through PHE duty doctor on 020 8200 6868.

Clinical Management

Specialist advice should be urgently sought from an Infectious Diseases Physician.

Botulinum antitoxin is effective in reducing the severity of symptoms if administered early in the course of the disease. C. botulinum is sensitive to benzyl penicillin and metronidazole. In cases of wound infection, antimicrobial therapy and surgical debridement should reduce the organism load and therefore toxin production, but circulating toxin can only be neutralised by the early administration of antitoxin. Where there is definite clinical suspicion of botulism, treatment with antitoxin should not be delayed for microbiological testing. Antitoxin can be obtained from the Colindale site by contacting the duty doctor on 020 8200 6868.

Preventive Measures

The risk of death in individuals presenting with wound botulism may be reduced if supportive therapy and antitoxin are provided promptly. Increased awareness amongst clinicians may facilitate prompt diagnosis and treatment.

Wound botulism is thought to occur in people who inject drugs when heroin contaminated with C. botulinum spores is injected into sites that encourage anaerobic conditions. There is no way of telling if a supply of heroin (or other drugs) is contaminated with C. botulinum spores. The following advice may reduce the risk of wound botulism in people who inject drugs:

  • Smoking heroin instead of injecting may reduce the risk of wound botulism. However, because other infections such as Anthrax can result from smoking contaminated heroin, our advice is that smoking heroin should be avoided.
  • If possible try to stop using heroin.  Talk to a doctor or someone at a drug service about starting on a prescribed alternative drug (such as methadone or buprenorphine) and/or other treatment options.
  • If you must inject, do not inject into muscle or under the skin: make sure you hit the vein - your blood is better at killing this bacteria than your muscle.
  • Don't share needles, syringes, cookers/spoons or other 'works' with other drug users.
  • Use as little citric acid as possible to dissolve the heroin.  A lot of citric acid can damage the muscle or the body under the skin, and this damage gives bacteria a better chance to grow.
  • If you inject more than one type of drug, inject each at a separate place on your body and with clean works for each injection.  This is important because certain drugs (e.g. cocaine) could give bacteria in heroin a better chance to grow.
  • If you get swelling, redness, or pain where you have injected yourself, or pus collects under the skin, you should get a doctor to check it out immediately, especially if the infection seems different to others you may have had in the past.

Information for drug users Botulism infection in those who inject heroin (PDF, 33 KB)

Reporting and Public Health Investigation

Since food borne botulism constitutes a public health emergency, food must be excluded as a source for all cases of botulism. PHE has prepared a detailed questionnaire that CCDCs can use to obtain information on clinical presentation, food history and injecting behaviour from all suspected cases of botulism.

Food samples associated with suspected cases of food borne botulism must be obtained as a matter of extreme urgency in order to prevent further cases.

Samples of heroin can be tested by PHE for the presence of microbial contamination. If the police are in possession of drugs believed to be associated with suspected cases of wound botulism, please contact PHE FPRS on 020 8200 4400 ext 7117 to discuss arrangements for testing.

Clinicians and CCDCs are asked to report any suspected cases of botulism to PHE FPRS (020 8200 4400 ext 7117) or to the PHE duty doctor on 020 8200 6868.


Last reviewed: 23 October 2013